如何查看手头的东西(文件上传javascript)

How to check what in hand(file upload javascript)

我需要非常自定义的文件上传解决方案。有一个用户文件的树视图,我想将此树视图用作放置区。查看伪代码:

//divTreeView and divUploadText variables with html code
var tree = true;
('#treeView').hover(
    function() {
        if(userHoldFile()) {
            $('#treeView').html(divUploadText);
            tree = false;
    },
    function() {
        if(!tree) $('#treeView').html(divTreeView);
    }
);

因此,当用户将鼠标悬停在带文件的 treeView 上时,我想向他显示带有文本 drop file to upload 的 div,但是当他悬停在没有文件的区域时,它应该可以作为树视图。

问题重复。 Need event for "mouseover with file" for HTML5 Fileupload

文档 https://html.spec.whatwg.org/multipage/interaction.html#the-dropzone-attribute

我需要的例子

<div dropzone="copy file:image/png file:image/gif file:image/jpeg" ondrop="receive(event, this)">
 <p>Drop an image here to have it displayed.</p>
</div>
<script>
 function receive(event, element) {
   var data = event.dataTransfer.items;
   for (var i = 0; i < data.length; i += 1) {
     if ((data[i].kind == 'file') && (data[i].type.match('^image/'))) {
       var img = new Image();
       img.src = window.createObjectURL(data[i].getAsFile());
       element.appendChild(img);
     }
   }
 }
</script>